Electrocardiogram

An electrocardiogram (ECG or EKG) is a noninvasive test that records the electrical impulses of the heart. It assesses many aspects of heart health, including:

Heart rate and rhythm.
Heart muscle damage or defects.
Size and position of the heart chambers.

This test is simple, safe, and painless. It can be done as a routine part of a physical exam. It can also be done to evaluate symptoms such as severe chest pain and fast or irregular heartbeats (palpitations).

An ECG may also be done to monitor the effects of certain heart medicines or implanted devices used to control the heart, such as a pacemaker or defibrillator.

Tell a health care provider about:

Any allergies you have.
All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.

What are the risks?

There are no serious risks associated with this test.

What happens before the test?

No specific preparation is needed before this test.
Do not exercise or drink cold water right before an ECG because these actions may cause false results.

What happens during the test?

You will be asked to remove your clothes from the waist up and lie on your back.
Hair may be removed from the area of the skin where sticky patches (electrodes) will be placed.
Electrodes will be placed on your chest, arms, and legs.
Wires (leads) will be attached to the electrodes and then attached to the ECG machine. No electricity will be sent through your body.
You will be asked to relax and lie still for a few seconds while the ECG machine records the electrical activity of your heart.

The test may vary among health care providers and hospitals.

What can I expect after the test?

Your health care provider or a heart specialist (cardiologist) will interpret the recording.
It is up to you to get your test results. Ask your health care provider, or the department that is doing the test, when your results will be ready.

Summary

An electrocardiogram (ECG or EKG) is a test that records the electrical impulses of the heart.
An electrocardiogram assesses many aspects of heart health, including heart rate and rhythm, heart muscle damage or defects, and the effects of certain heart medicines or implanted devices used to control the heart.
This test is simple, safe, and painless. There are no serious risks associated with this test and no specific preparations needed before the test.

This information is not intended to replace advice given to you by your health care provider. Make sure you discuss any questions you have with your health care provider.